I think we're forgetting the purpose of this thread again. It is not to say which OS or gaming device would be nice to have Audiosurf on. It is so that people can discuss how it would be possible to get Audiosurf on something else, and how likely, but the main purpose is to keep people from starting threads asking for ports.
in that case, i'd like to conclusively state that it would be ENTIRELY possible to have a full-featured audiosurf clone on the iphone. let me state beforehand that i don't own or like iphones, so you can be certain that my judgment is not biased in the least.
let's take a look at past exploits in the genre of musical games: those games perhaps date back to the very beginning of game programming, as far as playing a tune goes. but that's not what we're after, we're pondering about the possibility of generating full levels based on any song thrown at the game. what do we have going for this?
the basic principle of audiosurf is a funky visualizer, that lets you ride on the generated waveform with all sorts of quirks and challenges thrown at you. it just so happens that we do have a match based on those criteria, and it appeared on none other than the playstation 1, exactly ten years ago: the game in question was vib-ribbon. it had minimalistic looks and levels generated upon loading the actual song, and this worked by swapping the game disc with the audio CD of your choice; all of this was accomplished with extremely minimal, optimized code that crammed the whole program into 2 MBs of RAM.
now, let me remind you that the PSX had a 33.8 MHz RISC processor; the iphone, on the other hand, has 128 MB (shared) of RAM, and its ARM CPU clocks in at 400 MHz; if we slice out the reserved memory areas from the equation, that's roughly 40 times as much available RAM as the old PSX was capable of, and twelve times the CPU speed (although admittedly, the ARM CPU has a much more extended instruction set than the somewhat streamlined PSX one). that's a lot of wiggle room to cram a well-optimized engine into, capable of handling the whole track-processing and visualization (although, of course, in much rougher detail) the PC version can juggle.
as a corollary, we could conclude that if dylan was capable of tapping console hardware properly, it would be definitely possible to come up with a great audiosurf port for most systems, maybe down to the PS2 (294.912 EE CPU/32 MB RDRAM), although in the latter case with very limited visuals since the game would have to again swap from CD.
note that i intentionally left out the graphical details from my observations, keeping the speculation and technical specs for those in careful check: i take it for granted that there will have to be cuts to the current visuals, since these systems are not capable of munching enough video data to rival a voodoo 2; additionally, i'm assuming that dylan wouldn't have a thorough enough knowledge of any given system to come up with highly optimized code, that usually happens when a developer works with a certain platform on a stable basis (absolutely no offense intended towards a great coder, that's just how things are with so many different architectures around
; but that's not even the point here.
point is, it would be completely possible to have a full-featured port of this game on any system, provided that there was no need to deal with swapping the whole game data into RAM and that its specs were at least reasonable. as you can see, even 33 MHz are just enough to crunch a song and generate the corresponding stage (although the guys at NaNaOn-Sha already knew the PSX's hardware beforehand, having worked on parappa the rapper before, and were probably hardcore coding ninjas to pull that off; also, that game's visuals were VERY minimalistic, think vector-based but with more pixellation); that's really not the worst barrier here. the actual problem is the availability of a reliable engine to work with, and it remains to be seen if dylan's rumored "audiosurf mobile engine" will be capable of handling such different platforms swiftly.
that said, it would also be entirely possible to create a handheld port of this game; again, there's nothing crazy about pulling this one off. case in point, beats for the PSP; it's another game capable of analyzing audio data and creating a barebones stage to play, with nice visuals to boot. it's also to be noted that the PSP has better graphics than the iphone, in spite of the lower CPU clock, giving room for some extra eye-candy (also, don't quote me on this, but i think that in this case the visuals are handled by the CPU itself, which might complicate things a little -- but not by much). on the other hand, the DS implements an ARM CPU as well; if he's working on an ARM-based engine, it shouldn't be too hard to fiddle around and tweak it to work with that platform too. well, that's it, i hope my observations weren't too boring for anyone's comfort
